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A linearized analytic model of general longitudinal movement of airplane is discussed. Linearized deviation equations of motion, derived in stability axes system, are applied to the parametric analysis of airplane's longitudinal dynamic stability under arbitrary symmetric flight conditions. The analytic model is generated in the form of interactive software package PODYST_ALFA. This is used to show the influence of some constructional and mass parameters on the longitudinal airplane motions after encountering disturbance for a chosen steady level flight.

The purpose of this paper is to present the research efforts of the Center of Aeronautical Studies of the Federal University of Minas Gerais – Brazil to develop a low‐cost flight test data acquisition system for light aircraft and unmanned aerial vehicles (UAEs).

The development of this system was based on a microcontroller, chosen in accordance with main requirements of light aircrafts flight tests. The system uses the microcontroller in order to communicate with different kinds of sensors, including a GPS, and organize this information to be sent to a PDA device, which is used to control the acquisition process and storage the data acquired. Details about the development of this system, including firmware algorithm and sensors development, are presented and discussed in the paper.

The paper presents example results obtained with this system in applications such as performance evaluation and stability and control derivatives estimation problems. Take into account all the aspects of the system and the quality of the results, the main conclusion is that this system can efficiently support the demands of the aerospace industry for light aircraft and UAEs development programs as well as the necessities of the research centers and universities developing aeronautical research and didactic programs.

Recently, results confirm the applicability of this system in order to perform flight tests of aircrafts in accordance with FAR‐Part 23 or CS‐VLA or Light Sport Aircrafts as required by FAA Order 8130.2F and ASTM Designation F2245‐04.

This paper presents details about the construction of a low‐cost data acquisition system for flight tests of light aircrafts. The main advantage of this system is the use of a PDA device in order to control and storage the acquisition, which reduce costs, weight and size of the system and permits its installation in light aircrafts or UAVs.

The finite element model developed for a new-designed aircraft was used to solve some problems of structural dynamics. The key purpose of the task was to estimate the critical flutter velocities of the light airplane by performing numerical analysis with application of MSC Software.

Flutter analyses processed by Nastran require application of some complex aeroelastic model integrating two separate components – structural model and aerodynamic model. These sub-models are necessary for determining stiffness, mass and aerodynamic matrices, which are involved in the flutter equation. The aircraft structural model with its non-structural masses was developed in Patran. To determine the aerodynamic coefficient matrix, some simplified aerodynamic body-panel geometries were developed. The flutter equation was solved with the PK method.

The verified aircraft model was used to determine its normal modes in the range of 0-30 Hz. Then, some critical velocities of flutter were calculated within the range of operational velocities. As there is no certainty that the computed modes are in accordance with the natural ones, some parametric calculations are recommended. Modal frequencies depend on structural parameters that are quite difficult to identify. Adopting their values from the reasonable range, it is possible to assign the range of possible frequencies. The frequencies of rudder or elevator modes are dependent on their mass moments of inertia and rigidity of controls. The critical speeds of tail flutter were calculated for various combinations of stiffness or mass values.

The task described here is a preliminary calculational study of normal modes and flutter vibrations. It is necessary to prove the new airplane is free from flutter to fulfil the requirement considered in the type certification process.

The described approach takes into account the uncertainty of results caused by the indeterminacy of selected constructional parameters.

THE concept of an ‘all‐plastics’ airframe has been possible of achievement since the early 1940s but, apart from some special applications, such as radar and radio transparencies, bearings, fuel tanks, etc., the introduction of reinforced bonded materials has been extremely slow. Curiously, and despite the intense pressures of technological advances, the aircraft industry is conservative and many innovations which can be seen in retrospect to have been inevitable, have been held back for years until they have been forced on the designers by circumstances. Cases in point are the time taken to abandon the biplane to accept wing flaps and to adopt variable‐pitch propellers. Even the jet engine was, for a long time, squeezed into airframes of obviously unsuitable shape. Nevertheless, it seems surprising that it has taken some twenty years to bring the use of plastics for major airframe components to the stage of practical proof.

This paper presents the longitudinal stability analysis of a single tractor propeller airplane LASTA at high engine power settings. This analysis is part of the ongoing process of certifying the airplane for civil use according to the civil regulations CS-23.

The design methodology that is presented in the paper consists of comparing flight test aerodynamic and calculation results. The methods used here are standard and routinely used in flight testing.

Flight testing results indicate that at low airspeeds the cumulative destabilizing effects because of high values of the angle of attack and high power settings are about 6 per cent of MAC. This value is in a very good agreement with published data.

The information presented in this paper are new, and are very specific to this one aircraft configuration. The methods used here are standard and widely used in flight testing.

The information in this paper presents flight test results. There are not many publications in this area.

The paper aims to detail the educational flight testing activities performed at the Department of Aerospace Science and Technology at the Politecnico di Milano (DSTA-PoliMi), including the development of low-cost, reliable flight testing instrumentation (FTI) and the administration of the graduate course in flight testing.

The flight testing course program closely adheres to the typical content of an introductory course offered in a professional flight testing school. However, within academic courses, it has a unique feature: each student is required to plan, perform and report on a real flight test experience, acting as a flight test engineer. Educational activities in this framework have been successfully matched to applied research and technical support for private companies.

At the educational level, several elements arise that are rarely concentrated within a single course, such as multidisciplinary integration, individual conceive-design-implement-operate (CDIO) project, real-life experimental procedures and techniques, teamwork, communication and reporting, relation with non-academic partners.

Based on the development of a FTI system for light aviation and on the flight testing course, DSTA-PoliMi has built a solid capability in flight testing, introducing graduate students to this specific niche of expertise and empowering co-operation with companies in the light aviation environment, while offering capabilities and tools that are typically regarded as a prerogative of major aerospace companies.

The paper discusses an original approach to flight testing education in an academic setting that avoids the high costs and complexity connected to certified aircraft flight operations and instrumentation, nevertheless allowing the achievement of significant results, also in applied engineering research.

This paper aims to present the new information about propeller thrust force contribution to airplane longitudinal stability analysis.

The method presented in this paper is empirical, shows how propeller thrust force derivative can be obtained and gives some additional information about misinterpretation of the propeller thrust effects that are present in the current literature.

New information about propeller thrust force contribution to airplane longitudinal stability analysis has been presented. This information should enable more precise insight in aircraft stability analysis and better understanding of the physical process that occurs during maneuver flight.

The information presented in this paper is new and specific to the propeller aircraft configuration. The methods used here are standard procedure to evaluating propeller thrust force derivative.

The information in this paper presents theoretical results. The method for calculating thrust force contribution to the airplane longitudinal stability is given depending on the propeller type and should enable good engineering results.

The purpose of this paper is to focus on the finite element (FE) analyses undertaken for aerodynamically and structurally optimized design of a modern, lightweight civil unmanned air vehicle (UAV) made fully of composite materials.

The FE method has been applied to design and calculate the safety factors of all structural elements of the UAV. Fully parameterized design tools have been developed in the preliminary design phase, allowing automatic reshapes of the skin and the internal structural parts, wherever needed, to achieve optimal structural design, from the point of view of lightweight and structural integrity. Monotonic and fatigue tests have been performed on material specimens with various thicknesses and fibre textures, to verify the material properties used for the FE analyses. The load assumptions were in accordance with the valid international standards.

The material tests confirmed the validity of the material properties used within the FE calculations. The calculated safety factors were acceptable for all structural elements and components of the UAV. As a result, a lightweight, structurally optimized design has been achieved, considering the international, standardized specifications assumptions and fulfilling the safety requirements.

Design engineers may use the outcomes of this work as a guide to achieve optimal lightweight structures ensuring its operational strength using composite, lightweight materials.

A new, structurally optimized, lightweight aircraft design has been developed, able to accommodate heavy electronic payloads while being able to fly for over ten hours without refuelling. This medium altitude long endurance airplane can overview forests, seas and human trafficking autonomously and economically.

THE life of an engineer is largely a life spent in solving problems of a practical kind; and so his attitude to nature differs from that of the scientist. Confronted with a particular material an engineer will first ask in what way he can use its particular and special properties; whereas the scientist will want to know how those particular and special properties arise. But a good engineer must have knowledge of the scientist's conclusions, so I hope engineers will not think I am wasting time by trying to describe in these articles why wood behaves like wood and why rubber is “rubbery.” I have tried to keep the engineer's point of view in mind, and I have not attempted to give anything more than an outline of the reasons why a given material has its special and peculiar properties.

The purpose of this paper is to simulate with in-depth reconstruction of existing geometry a process of cooling of the aircraft engine in pusher configuration, which is more problematic than usually used, tractor configuration. Moreover, a complex thermal and fluid flow analysis is necessary to verify that an adequate cooling is ensured and that temperatures in the engine nacelle are maintained within the operating limits.

Methodology used in this research is based on computational fluid dynamics tools to model adequately the internal and the external flow, to find the state of cooling system and research the results of baffles modification inside the engine cover. Additionally, two types of the cover with different sizes of inlets and outlets are tested.

The results showed the influence of baffles modifications and changes in inlets and outlet sizes on the mass flow rate and temperature distributions inside the engine nacelle. The best configuration of air inlets and outlets was determined.

The method used in the research is the safest method in testing of such cases, provided the proper approach in modeling is taken. The collaboration of internal and external flow is crucial and should not be replaced with assumed flow rate through inlet and outlet area. The obtained results will help in future studies on cooling systems of engines in pusher configuration.

The work presents original results obtained by the authors during a complex fluid flow and heat transmission analysis and is a part of the design project of the OSA patrol aircraft.